progs/trivial/tri-edgeflag.c

   1 /*
   2  * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and
   5  * its documentation for any purpose is hereby granted without fee, provided
   6  * that (i) the above copyright notices and this permission notice appear in
   7  * all copies of the software and related documentation, and (ii) the name of
   8  * Silicon Graphics may not be used in any advertising or
   9  * publicity relating to the software without the specific, prior written
  10  * permission of Silicon Graphics.
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
  13  * ANY KIND,
  14  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  15  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  16  *
  17  * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
  18  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  19  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  20  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  21  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  22  * OF THIS SOFTWARE.
  23  */
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28 #include <GL/glut.h>
  29
  30 static GLenum doubleBuffer;
  31 static GLenum frontface = GL_CCW;
  32
  33 static void Init(void)
  34 {
  35    fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
  36    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
  37    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
  38 }
  39
  40 static void Reshape(int width, int height)
  41 {
  42     glViewport(0, 0, (GLint)width, (GLint)height);
  43
  44     glMatrixMode(GL_PROJECTION);
  45     glLoadIdentity();
  46 /*     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0); */
  47     glMatrixMode(GL_MODELVIEW);
  48 }
  49
  50 static void Key(unsigned char key, int x, int y)
  51 {
  52    switch (key) {
  53    case 'f':
  54       frontface = (frontface == GL_CCW) ? GL_CW : GL_CCW;
  55       glFrontFace(frontface);
  56       break;
  57    case 27:
  58       exit(1);
  59    default:
  60       return;
  61    }
  62
  63     glutPostRedisplay();
  64 }
  65
  66 static void Draw(void)
  67 {
  68    glClear(GL_COLOR_BUFFER_BIT);
  69    glPolygonMode(GL_FRONT, GL_LINE);
  70    glPolygonMode(GL_BACK, GL_POINT);
  71
  72    glBegin(GL_TRIANGLES);
  73    glEdgeFlag(1);
  74    glColor3f(0.3,0.3,.9);
  75    glVertex3f( 0.9, -0.9, -0.0);
  76    glEdgeFlag(0);
  77    glColor3f(.8,0,0);
  78    glVertex3f( 0.9,  0.9, -0.0);
  79    glEdgeFlag(1);
  80    glColor3f(0,.9,0);
  81    glVertex3f(-0.9,  0.0, -0.0);
  82    glEnd();
  83
  84    glFlush();
  85
  86    if (doubleBuffer) {
  87       glutSwapBuffers();
  88    }
  89 }
  90
  91 static GLenum Args(int argc, char **argv)
  92 {
  93     GLint i;
  94
  95     doubleBuffer = GL_FALSE;
  96
  97     for (i = 1; i < argc; i++) {
  98         if (strcmp(argv[i], "-sb") == 0) {
  99             doubleBuffer = GL_FALSE;
 100         } else if (strcmp(argv[i], "-db") == 0) {
 101             doubleBuffer = GL_TRUE;
 102         } else {
 103             fprintf(stderr, "%s (Bad option).\n", argv[i]);
 104             return GL_FALSE;
 105         }
 106     }
 107     return GL_TRUE;
 108 }
 109
 110 int main(int argc, char **argv)
 111 {
 112     GLenum type;
 113
 114     glutInit(&argc, argv);
 115
 116     if (Args(argc, argv) == GL_FALSE) {
 117         exit(1);
 118     }
 119
 120     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 121
 122     type = GLUT_RGB | GLUT_ALPHA;
 123     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 124     glutInitDisplayMode(type);
 125
 126     if (glutCreateWindow(*argv) == GL_FALSE) {
 127         exit(1);
 128     }
 129
 130     Init();
 131
 132     glutReshapeFunc(Reshape);
 133     glutKeyboardFunc(Key);
 134     glutDisplayFunc(Draw);
 135     glutMainLoop();
 136     return 0;
 137 }